In the usual building or construction project, considerable trenching and digging normally are required as a part of such work as pouring concrete footings and foundations, laying water lines, installing drainage tile and sewer pipes and systems, uncovering existing utility pipes and lines, waterproofing and reinforcing existing foundations, and the like. Much of this trenching and digging is accomplished by the use of an earth working machine designed primarily for that type of work, such as a backhoe or similar machine equipped with a hydraulically operated boom provided at its distal end with a bucket capable of digging into and picking up and removing dirt, rocks, rubble, and like materials (all hereinafter generally called "dirt"). The cutting edge of the bucket is provided with a row of outwardly projecting heavy duty pointed teeth designed to withstand considerable abuse and pressure in order to accomplish the ripping and cutting normally necessary to penetrate, break and pick up the dirt being excavated,
In a construction or building project of any significant size, use of a backhoe or similar boom equipped machine normally is used primarily for such work as digging and trenching and not for back filling, leveling or grading because of certain problems inherent in using a toothed bucket for such "finishing" work. Instead, a separate grader or end loader with a straight edge scraper blade normally is employed to push dirt back into the trenches and excavations and perform other leveling and grading operations around the construction site.
On smaller or emergency jobs requiring use of a backhoe, however, a separate grader or end loader seldom is available. This makes it necessary on such jobs to refill trenches and excavations and otherwise level and grade dirt either manually or with the backhoe, or using a combination of the two.
As those in the construction business are aware, the normal backhoe bucket is quite unsatisfactory for use in scraping dirt back into a trench or excavation or in leveling or grading a work area because of the presence of the teeth on the lower edge of the bucket. If the bucket is held high enough to avoid penetration of the teeth into the ground being cleared, considerable dirt is left behind and must then be raked or shoveled manually. Or if the bucket is lowered enough to scrape most of the dirt from the ground to be cleared, the teeth will penetrate into and tear and damage the ground, thus again requiring manual leveling and finishing.
In some cases, the operator may be able to position his or her backhoe and boom such that the side of the bucket can be used to scrape dirt back into a trench or excavation without excessively tearing up the ground being cleared. Even this contingency is far from satisfactory, however, as the bottom edge of the side of a bucket is relatively narrow, normally is curved and thus does not scrape evenly, and has no provision for preventing the "spill over" of dirt or other material from the sides of the bucket, thus necessitating an excessive number of passes of the bucket.
The problems discussed above have long been recognized by those in the field, and several proposals have been made for their solution. For instance, to adapt the usual toothed bucket for scraping and back filling, it has been suggested that a separate straight edge blade be positioned over and bolted, clamped or otherwise attached to the teeth or the bucket. For a variety of reasons, however, none of these prior proposals have proven satisfactory or met with any significant commercial success. Accordingly, until development of the present invention, the industry has continued to experience problems in trying to use the usual toothed backhoe bucket for back filling, scraping, leveling or otherwise grading dirt.